Apparatus for counting and stacking sheet material

ABSTRACT

Sheets of material, such as cardboard container blanks, are conveyed to a stacking station sequentially where they are stacked vertically from underneath, the sheets being counted by counter mechanism as they are delivered to the stacking station. When a desired number of sheets have been stacked, the counter activates mechanism to extend a finger under the stack. Continued stacking of sheets under the finger elevates the latter along with the overlying sheets to a position at which the finger effects activation of ejector mechanism which removes the counted stack from above the finger to an outfeed conveyor. The finger then is retracted and lowered to initial position for subsequent extension. When the desired number of sheets have been assembled into a second stack, the counter activates mechanism to extend a second finger under the stack. Continued stacking of sheets under the second finger elevates the latter to a position at which it effects activation of the ejector mechanism to remove the counted second stack from above the second finger. Additional fingers may be provided to continue the foregoing sequence, after which the cycling reverts to the first finger. Alternatively, a single finger may be provided for use with all stacks, if the rate of stacking accommodates it.

United States Patent [1 1 Nelson [451 Sept. 10, 1974 APPARATUS FOR COUNTING AND STACKING SHEET MATERIAL [76] Inventor: Victor R. Nelson, 2700 SW. Summit Dr., Lake Oswego, Oreg. 97034 22 Filed: Apr. 26, 1973 21 Appl. No.: 354,693

Primary ExaminerRoy Lake Assistant Examiner-James F. Coan [57] ABSTRACT Sheets of material, such as cardboard container blanks, are conveyed to a stacking station sequentially where they are stacked vertically from underneath, the sheets being counted by counter mechanism as they are delivered to the stacking station. When a desired number of sheets have been stacked, the counter activates mechanism to extend a finger under the stack. Continued stacking of sheets under the finger elevates the latter along with the overlying sheets to a position at which the finger effects activation of ejector mechanism which removes the counted stack from above the finger to an outfeed conveyor. The finger then is retracted and lowered to initial position for subsequent extension. When the desired number of sheets have been assembled into a second stack, the counter activates mechanism to extend a second finger under the stack. Continued stacking of sheets under the second finger elevates the latter to a position at which it effects activation of the ejector mechanism to remove the counted second stack from above the second finger. Additional fingers may be provided to continue the foregoing sequence, after which the cycling reverts to the first finger. Alternatively, a single finger may be provided for use with all stacks, if the rate of stacking accommodates it.

7 Claims, 5 Drawing Figures APPARATUS FOR COUNTING AND STACKING SHEET MATERIAL BACKGROUND OF THE INVENTION This invention relates to the counting and stacking of sheets of material, and more particularly to novel apparatus by which to count and stack sheets of material with speed and accuracy.

Sheet counting and stacking mechanisms of various types have been provided heretofore. In general, they function to count sheets of material by measuring the height of a stack of a desired number of sheets. Such means of counting is quite inaccurate, because of variations in sheet thickness and of the degree of flatness of the sheets. Moreover, when such mechanisms are used to count pre-folded container blanks to which adhesive has been applied and is still not fully set, they allow the blanks to be stacked in un-squared condition, which condition is rendered permanent upon final setting of the adhesive. Such un-squared blanks produce faulty containers which most often have to be discarded as unusable. Thus, in the use of such prior mechanisms it has been the practice to overcorrect in the stacking of sheets, to insure that the purchaser obtains a few more sheets than were ordered. These extra sheets, together with the sheets discarded as unusable, represent a sigtainers.

SUMMARY OF THE INVENTION In its broad concept, the apparatus of this invention involves the stacking of sheets of material from underneath, and utilizes a sheet counting device operable, when the stack has attained a desired number of sheets, to extend a retractable finger mechanism under the stack, the finger mechanism moving upward with the counted stack as additional sheets are stacked under the finger mechanism, until the latter reaches a point of elevation at which it activates ejector mechanism to withdraw the counted stack from above the finger mechanism, whereupon the latter is retracted and lowered to starting position for subsequent extension.

It is by virtue of the foregoing basic concept that the principal objective of this invention is achieved; namely, to overcome the aforementioned disadvantages of prior counting and stacking mechanisms.

Another important object of this invention is the provision of sheet counting and stacking apparatus which may be integrated into sheet processing apparatus of diverse types with maximum facility and minimum alteration.

A further important object of this invention is to provide sheet counting and stacking apparatus which is of relatively simplified construction for economical manufacture, which is precise in its operation and is capable of operation at high production rates.

The foregoing and other objects and advantages of this invention will appear from the following detailed description, taken in connection with the accompanying drawings of a preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary, foreshortened view in front elevation of sheet counting and stacking apparatus embodying the features of this invention.

FIG. 2 is a fragmentary, foreshortened sectional view taken along the line 2-2 in FIG. 1.

FIG. 3 is a fragmentary sectional view taken along the line 3-3 in FIG. 1.

FIG. 4 is a fragmentary sectional view taken along the line 44 in FIG. 1.

FIG. 5 is a schematic diagram of electrical and fluid pressure control circuitry for the apparatus of the preceding views.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The apparatus of this invention includes sheet delivery mechanism, herein illustrated as a plurality of laterally spaced endless conveyor belts 10 (FIG. 1) supported on spaced rollers 12, only one of which is shown. The rollers are supported at their ends by laterally spaced frame members 14. At least one of the rollers is driven to effect movement of the belts and the sheets 16 of material supported thereon in the direction of the arrow 18 shown in FIG. 2.

The apparatus also includes a sheet stacking station upon which the sheets of material from the delivery conveyor are stacked vertically from underneath. Referring particularly to FIG. 2 of the drawings, the stacking station illustrated includes a plurality of laterally spaced endless conveyor belts 20 mounted on spaced rollers 22 at least one of which is driven to move the conveyor belts-and the sheets delivered thereto the direction of the arrow 24. The infeed end portion 20 of the conveyor belts is angled upwardly from the plane of the delivery conveyor belts 10, by means of an intermediate roller 26, to effect upward movement of the sheets of material from the delivery conveyor to the stacking conveyor.

The stacking station also includes a transverse abutment member 28 against which the leading ends of the sheets of material are brought into engagement. This abutment member preferably is adjustable toward and away from the delivery conveyor so as to accommodate the stacking of sheets of material of various lengths. In all cases, the position of the abutment member is such that the trailing ends of the sheets of material overhang the inclined portion 20' of the stacking conveyor belt. This provides a wedge-shaped space between the inclined portion of the conveyor and the overhanging trailing portion of the lowermost sheet on the stacking conveyor, between which the leading end of the next succeeding sheet of material may enter and thus be drawn onto the stacking conveyor under the previously stacked sheets of material.

It will be understood that as each sheet is brought into engagement with the abutment 28, the stacking conveyor belts slide continuously under it as the belts continue to move in the direction of the arrow 24.

The sheet counting and stack ejecting mechanism of this invention is located adjacent the outfeed end of the delivery conveyor and includes a supporting framework comprised of a transverse beam 30 extending between the frame members 14 and a pair of laterally spaced plates 32 depending from the beam.

Finger mechanism is supported by the framework for movement between a retracted position rearwardly of sheet material stacked on the stacking station and an extended position in which a finger component underlies a trailing edge portion of stacked sheet material to isolate the stack of sheets above the finger component from the sheets below it. In the embodiment illustrated, the finger mechanism includes a plurality of finger units, there being three such units 34, 36 and 38 illustrated. Each unit comprises a pair of laterally spaced finger assemblies each of which includes a finger component 40 mounted at the lower end of an elongated, vertically extending rod 42. Each rod extends slidably through a guide bore in a support block 44 for vertical movement freely therethrough. A keyway 46 in the rod and a key 48 in the block prevents axial rotation of the rod and thus maintains the finger component 40 in proper position.

A collar 42' adjacent the upper end of each rod 42 is arranged to abut the support block 44 and thus limit the downward movement of the rod relative to the block. The limit of upward movement of the rods is determined by the vertical position of microswitches 50, 52 and 54 the activators of which are disposed for abutment by the upper ends of one of the rods 42 of each finger unit, as explained more fully hereinafter.

The support blocks are mounted pivotally on shafts 56 secured to the plates 32 and extending inwardly therefrom. Each shaft supports one of the finger assemblies of each unit. Thus, the pair of inboard finger assemblies form one unit 34; the middle pair of finger assemblies form a second unit 36; and the outboard pair of finger assemblies form a third unit 38.

Drive means is connected to each pivoted block for pivoting the latter about its mounting shaft. In the embodiment illustrated, each drive means comprises a fluid pressure cylinder 58 mounted pivotally at one end on a pivot shaft 60 projecting inward from the plates 32. The piston rod projecting from the opposite end of the cylinder is connected pivotally to the associated block by means of a pivot pin 62. Thus, by the appropriate application of fluid pressure, either pneumatic or hydraulic, to the opposite ends of the cylinder, the block is caused to pivot so as to move the associated finger component 40 between the retracted position illustrated in full lines in FIG. 3 and the extended position illustrated in broken lines in FIG. 3. Fluid pressure is applied simultaneously to both cylinders associated with the pair of finger assemblies forming a unit, to effect simultaneous movement of the pair of assemblies, as will be understood. Further, fluid pressure is applied sequentially to the cylinders of each unit, by control mechanism described hereinafter, so that the finger components of each unit are moved to the extended position sequentially, for purposes also described hereinafter.

The apparatus of this invention also includes means for removing from the stacking station a stack of a predetermined number of sheets 16 of material. The ejector means illustrated includes an ejector plate 64 located between the inboard pair of finger assemblies forming the inboard finger unit 34. The plate extends vertically and is supported by a pair of laterally spaced plates 66 each of which supports a pair of horizontally spaced rolls 68 which extend inwardly therefrom. These rolls are received within laterally spaced channel-shaped tracks 70 which are secured to the transverse beam 30 and extend horizontally over the stacking station.

Drive means is provided for moving the ejector plate horizontally between a retracted position rearward of a stack of sheet material on the stacking station (FIGS.

'2 and 3) and an extended position toward the abutment member 28 for withdrawing the stack of sheet material from above the extended finger components 40. In the embodiment illustrated, such drive means comprises a fluid pressure cylinder 72 mounted at its rearward end pivotally on a bracket secured to the transverse beam. The piston rod projecting from the opposite end of the cylinder is connected pivotally between a pair of brackets (FIG. 4) projecting from the rearward side of the ejector plate. Accordingly, appropriate application of fluid pressure to the opposite ends of the cylinder 72 effects horizontal movement of the ejector plate be tween said retracted and extended positions.

In the extended position of the ejector plate the counted stack of sheets overlying the extended finger components 40 is moved forwardly over the abutment 28 and onto an outfeed conveyor. In the embodiment illustrated, the outfeed conveyor comprises a plurality of laterally spaced endless belts 74 mounted on longitudinally spaced rollers 76 at least one of which is driven in the direction of the arrow 78 illustrated in FIG. 2.

Also in the extended position of the ejector plate, one of the mounting plates 66 engages a normally open microswitch 80 mounted at the forward end of one of the tracks 70. As described hereinafter, the microswitch functions to effect return of the ejector plate to the retracted position illustrated in FIGS. 2 and 3.

Means preferably is provided for maintaining the stack of sheets on the stacking station in slightly compressed condition, to prevent inadvertent displacement of the sheets from their vertically aligned condition. In the embodiment illustrated, such means is provided by a set of rollers 82 mounted coaxially on a shaft 84 traversing a yoke 86 on a bottom end of a vertically elongated rod 88. The rod extends slidably through a vertical sleeve 90 mounted on a bracket 92 secured to a transverse spacer plate extending between the forward ends of the guide tracks 66. A longitudinal key slot 94 in the rod is engaged by a key 96 mounted in a threaded opening in the sleeve and secured therein by a lock nut 98. The key and key slot prevent axial rotation of the rod, whereby to maintain the axis of the roller shaft 84 perpendicular to the direction of outfeed movement of the stack by the ejector plate.

Means also is provided for squaring the leading and trailing ends of sheet material 16 delivered to the stacking station. Such means is particularly useful when the apparatus is employed to count and stack cardboard container blanks which have been previously folded and adhesive has been applied to the appropriate tabs. As previously mentioned, it often occurs that the folding of the blanks is sufficiently inaccurate that the tabs are not properly aligned to result in the ultimate formation of a properly square container. However, it has been found that this condition can be corrected by squaring the trailing end of the container blank with the leading end, before the adhesive has fully set, thereby allowing the adhesively coated tabs to slide relative to the adjacent portion of the blank to which it is to be secured. When the trailing end of the blank is squared with the leading end, the tabs also are brought into properly squared condition.

In the embodiment illustrated, the squaring means comprises a plurality of laterally spaced bumper sections 100 secured to a transversely elongated beam 102. The spaces between the bumper sections are aligned with and allow reciprocation of the finger units, as shown in FIG. 1. The beam is supported at the lower ends of a pair of laterally spaced arms 104. These arms are mounted pivotally adjacent their upper ends on pivot shafts 106 supported by the side plates 32 of the frame. Each arm mounts an outwardly projecting shaft 108 to which is journaled one end of a rod 110 (FIG. 2) the opposite end of which is coupled to an annular bushing 112. The bushing receives a circular cam disc 114 for rotation therein, and the cam disc is secured eccentrically to a drive shaft 116 mounted for rotation in the side plates 32 of the frame. The shaft preferably extends transversely through both side plates and is ex tended laterally at one end for connection to a drive motor (not shown).

Thus, upon activation of the drive motor, the shaft 116 is caused to rotate the eccentric cam discs 114, with consequent reciprocation of the transverse bumper 100 toward and away from the abutment member 28. The bumper engages the trailing ends of the carton blanks stacked on the stacking station, thereby urging said trailing ends into parallel alignment with the leading ends.

The operation of the apparatus described hereinbefore now will be described with particular reference to the schematic diagram illustrated in FIG. 5. For this purpose, let it be assumed that all of the finger units are in retracted position, that cardboard container blanks 16 having prefolded and preglued tabs are to be assembled into stacks of a predetermined number of blanks and the stacks are then to be ejected sequentially from the stacking station to the outfeed conveyor 74.

Accordingly, the aligning bumper 100 is reciprocated continually by activation of the drive motor connected to the shaft 116. The delivery conveyor 10, stacking station conveyor 20 and outfeed conveyor 74 also are activated for movement in the directions of the arrows, as previously explained.

The prefolded cardboard container blanks 16 are conveyed on the delivery conveyor sequentially in slightly spaced-apart condition. As they approach the stacking station conveyor, they are counted. In the embodiment illustrated in FIG. 5, the means for counting the blanks comprises an electric lamp 120 arranged with its beam 122 of light directed to a photocell 124 spaced from the lamp so that the blanks 16 may pass therebetween. As the space between successive blanks comes into alignment with the path of the light beam, the latter is impressed upon the photocell. The photocell thus is activated to provide an electric output signal which is fed to the input of an electronic counter mechanism 126.

When a predetermined number of electric signals are received by the counter mechanism, the latter produces an electric output signal, preferably in the form of an electric pulse. There are many types of such counter mechanisms commercially available, and it is preferred to utilize a type which is adjustable over a relatively wide range of counts. Thus, for example, the counter mechanism may be adjustable to provide an output pulse after each successive count of five to 50 sheets, in increments of five sheets.

As each blank is thus counted, it is delivered to the stacking station. lts leading end is directed upward along the inclined portion 20' of the stacking station conveyor belt 20 and moved forwardly into engagement with the transverse abutment member 28. The next succeeding blank enters the stacking station underneah the preceding blank, whereby the stack is built up from underneath.

As the stack of blanks builds up on the conveyor station, the trailing ends of the blanks are subjected to the intermittent pressure of the reciprocating bumper 100, whereby to align the trailing ends of the blanks with the leading ends and thus properly square the tabs of the prefolded blanks while the glue or adhesive is still not fully set.

When the counter mechanism reaches the preset count of blanks, it functions momentarily to connect a relay coil 128 across the terminals 130 and 132 of a source of electric potential. This pulse of electric potential energizes the coil momentarily to transfer its associated contacts A and B from the positions illustrated in FIG. 5.

Thus, the momentary closing of the normally open contact A completes the electric circuit of a stepper relay 134. Activation of the latter thus functions to close the associated contact A.

Simultaneously with the closure of the contact A of the relay coil 128, opening of the associated contact B deenergizes a timer relay coil 136, momentarily closing its associated contact. Accordingly, with the closure of the stepper relay contact A and the contact associated with the timer relay, the electric circuit of relay coil 138 is completed, with consequent closure of its associated contact. Closure of this contact completes the electric circuit of a relay coil 140, with resultant closure of its associated contact. Closure of this contact completes a holding circuit for its associated coil 140 through the normally closed contact A of a relay coil 142. Accordingly, the relay coil 140 is maintained energized even though the contact of relay coil 138 is opened following deenergization of the latter upon opening of the contact of the timer relay coil 136.

The timer relay is of the type which, when the coil 136 is denergized, effects immediate closure of its associated contact but which, when energized, effects opening of the associated contact only after a predetermined short time delay. Accordingly, the momentary activation of the relay coil 128 and the corresponding opening of its associated contact B effects simultaneous closure of the contact associated with the timer relay coil 136. When the relay coil 128 is deenergized after said momentary activation, the resulting closure of its associated contact B effects energization of the timer relay coil, but delayed opening of its associated contact. This insures proper activation of the relay coil '140 and its associated holding circuit, before deactivation of the relay coil 138.

Activation of the relay coil 140 and closure of its associated contact also effects completion of the electric circuit of a solenoid 144 associated with a fluid pressure valve 146. This valve thus is moved to the position in which fluid under pressure from a source (not shown) is delivered to the rearward ends of the cylinders 58 associated with the innermost finger unit 34 (FIG. 1). The latter thus are pivoted forwardly to the extended position, with the finger components 40 underlying the trailing end of the lowermost blank 16 in the counted stack on the stacking station. The extended fingers thus isolate the precounted stack of blanks from additional blanks being delivered to the stacking station and stacked under the extended fingers.-

As additional blanks are stacked on the stacking station, the extended fingers are moved upwardly with the overlying stack of blanks. This upward movement of the fingers is accommodate because the supporting rods 42 are slidable freely in the associated openings in the blocks 44.

Let it now be assumed that the extended fingers have been moved upwardly, by the continued stacking of blanks underneath them, to the position at which the upper end of one of the rods 42 engages the actuator of the electric switch 50 and causes closure of the latter before the underlying second stack has attained the predetermined number of blanks which would effect extension of the second, intermediate finger unit 34. This condition is illustrated in FIGS. 2 and 3, wherein the first stack of blanks, overlying the extended first pair of finger components consist of twenty blanks. The number of additional blanks underlying the first stack does not yet total twenty.

Closure of the switch by the finger rod 42 completes the electric circuit of relay coil 142 and consequent transfer of its associated contacts A and B from the positions illustrated in FIG. 5. Thus, opening of the normally closed contact A effects opening of the holding circuit of the relay coil and also opening of the electric circuit of the solenoid 144 of the fluid pressure valve 146. The valve thus is moved to the position at which fluid pressure is delivered to the forward ends of the associated cylinders 58. This results in retraction of the extended finger components 40, whereupon the latter gravitate downward as the rods 42 slide freely through their supporting blocks 44 until the collars 42' adjacent the upper ends of the rods abut the blocks. The finger components thus are in the lowered position ready for subsequent extension when required.

Simultaneously with the foregoing retraction of the extended fingers, by opening of the contact A of the relay coil 142, closure of the associated contact B completes the electric circuit of a relay coil 148 and consequent transfer of its associated contacts A and B from the normally open positions illustrated in FIG. 5. Closure of contact A completes a holding circuit for the relay coil 148 through the normally closed switch 80 located at the forward end of one of the guide tracks 70 for the ejector plate 64. Closure of contact B of relay coil 148 completes the electric circuit of the solnoid of a fluid pressure valve 152 for the ejector cylinder 72. Activation of this solenoid results in movement of the valve to the position in which fluid pressure is delivered to the rearward end of the cylinder 72, causing forward extension of the ejector plate 64. The plate thus abuts the trailing ends of the blanks in the stack overlying the extended finger components 40 and moves the stack forwardly over the transverse abutment member 28 and onto the outfeed conveyor 74.

When the ejector plate 64 reaches its position of maximum forward extension, it engages and opens the switch 80. This opens the holding circuit for the relay coil 148, whereupon its associated contacts A and B are returned to the normally open positions illustrated in FIG. 5. Opening of the contact B effects deenergization of the solenoid 150 of valve 152. The latter thus is moved to the position in which fluid pressure is applied to the forward end of the cylinder 72 to effect retraction of the ejector plate 64 to the position illustrated in FIGS. 2 and 3.

The foregoing sequence of operation is repeated as each subsequent stack of blanks of predetermined number is elevated to ejection position.

It will be apparent from FIGS. 2 and 3 that when it is desired that each stack include twenty blanks, for example, only a single finger unit need be provided, since sufficient time is available for retraction of the finger unit and subsequent extension of it to underlie the next subsequent stack of twenty blanks. However, let it now be assumed that it is desired that each stack be made up of only 10 blanks. Thus, since insufficient time is available for retraction and subsequent extension of a single finger unit before a second stack of 10 blanks is completed, the use of a second finger unit is required. This is for the reason that, in the condition illustrated in FIGS. 2 and 3, there are already nine blanks stacked under the first finger unit and the 10th blank is about to be added to the stack.

Thus, upon addition of the tenth blank to the stack, the counter 126 functions as previously described to energize the relay coil 128 momentarily, thereby activating the stepper relay coil 134. The stepper thus operates to close the second associated contact B and open the first contact A. Closure of stepper contact B effects energization of the relay coil 154, and the consequent closure of its associated contact effects energization of the relay coil 156. Closure of its associated contact forms a holding circuit for the coil through the normally closed contact A of relay coil 158 and also activation of the solenoid 160 for the fluid pressure control valve 162 associated with the pair of cylinders 58 of the second finger unit 36. The finger components 40 of the second unit thus are extended under the trailing end of the second stack of ten blanks.

Let it now be assumed that the switches 50, 52 and 54 associated with the rods 42 of the finger units are elevated above the position illustrated in FIGS. 2 and 3, so that the uppermost first stack of blanks will not be ejected until a second stack has been completed and an additional number of blanks have been stacked on the stacking station below the finger components of the second finger unit. Accordingly, after the first stack has been ejected as explained hereinbefore, the second stack continues to be elevated as additional blanks are stacked thereunder in the process of making up the third stack of 10 blanks. When the counter 126 reaches the preset count of 10 blanks for the third stack, the relay coil 128 is energized momentarily to activate the stepper relay 134 and close the associated third contact C and open the second contact B. Closure of the third contact C effects energization of the relay coil 164 and consequent closure of its associated contact, thereby energizing the relay coil 166. Closure of the associated contact completes a holding circuit for the coil through normally closed contact of relay coil 168, and also effects activation of the solenoid of fluid pressure control valve 172 associated with the cylinders 58 of the third finger unit 38. The finger components 40 of the third unit thus are extended under the trailing end of the third stack of blanks on the stacking station.

When the second stack has been elevated to the position at which the rod 42 of the second finger unit 36 engages and closes its associated switch 52, the relay coil 158 is energized to transfer the associated contacts A and B from the positions illustrated in FIG. 5. In manner similar to the operation of the relay coil 142 previously described, opening of the contact A of relay 158 effects deactivation of the relay coil 156 and of the solenoid 160 of the fluid pressure valve 162 associated with the cylinders 58 of the second finger unit 36. The latter thus is retracted from under the second stack and returned to the lowermost position in readiness for subsequent use. Simultaneously, closure of contact B of relay 158 effects activation of relay coil 148 and solenoid 150 of valve 152, thereby ejecting the second stack to the outfeed conveyor 74.

In similar manner, when the third stack has been elevated to the position at which the rod 42 associated with the third finger unit 38 engages and closes its associated switch 54, the relay coil 168 is energized to effect transfer of its associated contacts A and B from the positions illustrated in FIG. 5. As will be understood, this results in deactivation of the relay coil 166 and of the solenoid 170 of the fluid pressure control valve 172 associated with the cylinders 58 of the third finger unit 38, and also activation of the solenoid 150 associated with the fluid pressure control valve 152 for the ejector cylinder 72.

It will be understood that, in the instant illustration, a fourth stack of blanks will have been completed on the stacking station before the third stack has been ejected. With the completion of the fourth stack, the counter 126 operates as previously described to close the stepper contact A to once again extend the finger components of the first finger unit 34.

Accordingly, it will be understood that the apparatus may include a single finger unit, or any number of additional finger units, as desired, to accommodate the counting, stacking and ejection of stacks containing any desired number of sheets.

From the foregoing it will be appreciated that this invention provides apparatus which is capable of counting, stacking and ejecting a wide variety of sheet materials in stacks of any desired number of sheets and on a high production basis. The apparatus is precise in its operation, assuring the formation of stacks of precise numbers of sheets. Moreover, the apparatus described includes means by which the stacking of cardboard container blanks are squared automatically, to substantially eliminate the production of misaligned or otherwise unusable containers.

It will be apparent to those skilled in the art that various changes may be made in the size, shape, number, type and arrangement of parts described hereinbefore without departing from the spirit of this invention.

Having now described my invention and the manner in which it may be used, I claim:

1. Apparatus for counting and stacking sheet material, comprising:

a. a sheet stacking station for stacking sheet material vertically therein,

b. sheet delivery means for deliverying sheets of material sequentially to the stacking station for stacking sheets vertically from underneath,

c. sheet counting means for counting the sheets of material delivered to stacking station,

d. finger means mounted adjacent the stacking station for vertical movement between predetermined lower and upper positions of elevation and for horizontal movement between a retracted position away from sheet material on the stacking station and an extended position underlying an edge of sheet material on the stacking station,

e. finger drive means engaging the finger means for moving the latter between said retracted and extended positions, the finger means including an elongated rod extending slidably through an apertured support connected to the finger drive means,

f. finger drive control means operable by the sheet counting means to activate the drive means to move the finger means to said extended position when a predetermined number of sheets have been stacked on the stacking station,

. ejector means mounted adjacent the stacking station for movement between a retracted position away from sheet material on the stacking station and an extended position in which it engages and moves a precounted stack of sheets of material away from the underlying extended finger means,

. ejector drive means engaging the ejector means for moving the latter between said retracted and extended positions, and

. ejector drive control means operable by the finger means when the latter has reached said predetermined upper position of vertical movement to effect extension of said ejector means.

2. The apparatus of claim 1 wherein the apertured support is mounted pivotally on a support frame for movement of the finger means between said retracted and extended positions, and the finger drive means is mounted on the support frame and connected to said apertured support.

3. Apparatus for counting and stacking sheet material, comprising:

a. a sheet stacking station for stacking sheet material vertically therein,

b. sheet delivery means for delivering sheets of material sequentially to the stacking station for stacking sheets vertically from underneath,

c. sheet counting means for counting the sheets of material delivered to stacking station,

d. finger means mounted adjacent the stacking station for vertical movement between predetermined lower and upper positions of elevation and for horizontal movement between a retracted position away from sheet materialon the stacking station and an extended position underlying an edge of sheet material on the stacking station, the finger means including a plurality of finger units,

. finger drive means including a drive unit engaging each finger unit for moving the latter between retracted and extended positions,

f. finger drive control means operable by the sheet counting means to activate each finger drive unit sequentially to move each finger unit to said extended position when a predetermined number of sheets have been stacked on the stacking station, ejector means mounted adjacent the stacking station for movement between a retracted position away from sheet material on the stacking station and an extended position in which it engages and moves a pre-counted stack of sheets of material away from the underlying extended finger unit,

ejector drive means engaging the ejector means for moving the latter between said retracted and extended position, and i. ejector drive control means operable by each finger unit when the latter has reached said predetermined upper position of vertical movement to effect extension of said ejector means,

4. The apparatus of claim 3 including electric actuator means for each finger drive unit, the finger drive control means including switch means in the electric circuit of each finger drive actuator means operable sequentially by the sheet counting means to effect extension of each finger unit.

5. The apparatus of claim 4 including second switch means in the electric circuit of each finger drive actuator means operable by the associated finger unit at said predetermined upper position of vertical movement to effect retraction of said finger unit.

6. The apparatus of claim 3 including electric actuator means for the ejector drive means, the ejector drive control means including switch means in the electric circuit of the electric drive actuator means operable by each finger unit to effect extension of the ejector means.

7. The apparatus of claim 3 wherein:

a. the sheet supporting plane of the sheet delivery means is below the sheet supporting plane of the sheet stacking station and the latter is arranged to support a sheet of material with an end portion of the latter projecting beyond the stacking station, and each finger unit is positioned for extension under said projecting end portion of sheet material,

b. the sheet stacking station includes abutment means for engagement by the leading end of sheet material delivered to the stacking station, the abutment means being adjustable toward and away from the delivery means for accommodating the stacking of sheet material of different lengths,

. the sheet stacking station also includes bumper the finger drive control means includes switch means in the electric circuit of each finger drive actuator means operable sequentially by the sheet counting means to effect extension of the associated finger unit,

. second switch means is included in the electric circuit of each finger drive actuator means operable by the associated finger unit at said predetermined upper position of vertical movement to effect retraction of said finger unit,

electric actuator means is provided for the ejector drive means, and

the ejector drive control means includes switch means in the electric circuit of the ejector drive actuator means operable by each finger unit to effect extension of the ejector means. 

1. Apparatus for counting and stacking sheet material, comprising: a. a sheet stacking station for stacking sheet material vertically therein, b. sheet delivery means for deliverying sheets of matErial sequentially to the stacking station for stacking sheets vertically from underneath, c. sheet counting means for counting the sheets of material delivered to stacking station, d. finger means mounted adjacent the stacking station for vertical movement between predetermined lower and upper positions of elevation and for horizontal movement between a retracted position away from sheet material on the stacking station and an extended position underlying an edge of sheet material on the stacking station, e. finger drive means engaging the finger means for moving the latter between said retracted and extended positions, the finger means including an elongated rod extending slidably through an apertured support connected to the finger drive means, f. finger drive control means operable by the sheet counting means to activate the drive means to move the finger means to said extended position when a predetermined number of sheets have been stacked on the stacking station, g. ejector means mounted adjacent the stacking station for movement between a retracted position away from sheet material on the stacking station and an extended position in which it engages and moves a precounted stack of sheets of material away from the underlying extended finger means, h. ejector drive means engaging the ejector means for moving the latter between said retracted and extended positions, and i. ejector drive control means operable by the finger means when the latter has reached said predetermined upper position of vertical movement to effect extension of said ejector means.
 2. The apparatus of claim 1 wherein the apertured support is mounted pivotally on a support frame for movement of the finger means between said retracted and extended positions, and the finger drive means is mounted on the support frame and connected to said apertured support.
 3. Apparatus for counting and stacking sheet material, comprising: a. a sheet stacking station for stacking sheet material vertically therein, b. sheet delivery means for delivering sheets of material sequentially to the stacking station for stacking sheets vertically from underneath, c. sheet counting means for counting the sheets of material delivered to stacking station, d. finger means mounted adjacent the stacking station for vertical movement between predetermined lower and upper positions of elevation and for horizontal movement between a retracted position away from sheet material on the stacking station and an extended position underlying an edge of sheet material on the stacking station, the finger means including a plurality of finger units, e. finger drive means including a drive unit engaging each finger unit for moving the latter between retracted and extended positions, f. finger drive control means operable by the sheet counting means to activate each finger drive unit sequentially to move each finger unit to said extended position when a predetermined number of sheets have been stacked on the stacking station, g. ejector means mounted adjacent the stacking station for movement between a retracted position away from sheet material on the stacking station and an extended position in which it engages and moves a pre-counted stack of sheets of material away from the underlying extended finger unit, h. ejector drive means engaging the ejector means for moving the latter between said retracted and extended position, and i. ejector drive control means operable by each finger unit when the latter has reached said predetermined upper position of vertical movement to effect extension of said ejector means.
 4. The apparatus of claim 3 including electric actuator means for each finger drive unit, the finger drive control means including switch means in the electric circuit of each finger drive actuator means operable sequentially by the sheet counting means to effect extension of each finger unit.
 5. The apparatus of claim 4 including second switcH means in the electric circuit of each finger drive actuator means operable by the associated finger unit at said predetermined upper position of vertical movement to effect retraction of said finger unit.
 6. The apparatus of claim 3 including electric actuator means for the ejector drive means, the ejector drive control means including switch means in the electric circuit of the electric drive actuator means operable by each finger unit to effect extension of the ejector means.
 7. The apparatus of claim 3 wherein: a. the sheet supporting plane of the sheet delivery means is below the sheet supporting plane of the sheet stacking station and the latter is arranged to support a sheet of material with an end portion of the latter projecting beyond the stacking station, and each finger unit is positioned for extension under said projecting end portion of sheet material, b. the sheet stacking station includes abutment means for engagement by the leading end of sheet material delivered to the stacking station, the abutment means being adjustable toward and away from the delivery means for accommodating the stacking of sheet material of different lengths, c. the sheet stacking station also includes bumper means adjacent the infeed end thereof movable toward and away from the abutment means for engaging the trailing end of sheet material delivered to the stacking station for aligning said trailing end with the leading end thereof, d. electric actuator means is provided for each finger drive unit, e. the finger drive control means includes switch means in the electric circuit of each finger drive actuator means operable sequentially by the sheet counting means to effect extension of the associated finger unit, f. second switch means is included in the electric circuit of each finger drive actuator means operable by the associated finger unit at said predetermined upper position of vertical movement to effect retraction of said finger unit, g. electric actuator means is provided for the ejector drive means, and h. the ejector drive control means includes switch means in the electric circuit of the ejector drive actuator means operable by each finger unit to effect extension of the ejector means. 